I'm Curious what
@chromatose typical ride conditions are. That is an alarming and unusually high rate of failure on a Bosch motor. These bikes are not waterproof, just water resistant. Corrosion and rust take over quicker than most people realize and can quickly compromise an ebike motor, especially and an actively ridden mountain ebike.
Living in Cascadia, mountain biking can really challenge electrical components with water ingress. Bearings and gears are more easily compromised in addition to interfering with electrical connections and affecting continuity or causing outright shorts. Mountain bikes needs to be cleaned and dried out right away after getting wet gooey mud plastered on the bike and pushed into every nook and cranny
Extra care should be used in cleaning the bike, without using a pressure washer or a hard stream nozzle. always, rinsing with the water stream pointing down, starting top to bottom, and by placing a fan by the freshly washed bike to dry it off quicker and more thoroughly. Lube and grease need to be applied more often, especially in the kind of cold wet weather that has persisted around here since September.
Granted I am more obsessive about cleaning, lubrication and adhering to a rigorous maintenance schedule than most riders. I have had seven Bosch ebikes with a total of over 27,000 miles on them and not one problem with a motor. I don't know if I have just been lucky or my OCD has payed off.
